Hello and welcome to the forum!
More photos would help but, I am afraid this is likely a reproduction as Japanese swords are not constructed the same as damascus. Similar, but not the same.
Other members will be along shortly to either agree with me, or tell you I am wrong.
Searching for anything relating to, Anton Boos, 934 Stamm. Kp. Pz. Erz. Abt. 7, 3 Kompanie, Panzer-Regiment 2, 16th Panzer-Division (My father)
The numbers on the blade is not a good sign. I have never seen as genuine Japanese sword with numbers stamped in except military NCO swords. Take a picture of the entire tank with the end towards the point up. The tsuba likely had a dark finish that some moron polished off to make it "shiny."
LIFE'S LOSERS NEVER LEARN FROM THE ERROR OF THEIR WAYS.
Tsuba is bronze or brass and has a very slight magnetic property and for sure doesn't appear original to the rest of the fittings. Blade is well made damascus so for sure can use it to make a nice piece.
Chinese fake, given the acid etched characters..my opinion only, but seen many similar that were not the real thing.
Sorry you were defrauded by someone. There are butt loads of Chinese fakes in the market.
That is a Chinese made reproduction of a Japanese sword. There is nothing authentic Japanese about it in my view.